<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    img {
      display: block;
      width: 300px;
      margin: 200px auto;
      animation: jump .5s linear infinite alternate;
    }

    @keyframes jump {
      100% {
        transform: scale(1.2);
      }
    }
  </style>
</head>

<body>
  <img src="./images/1.jpg" alt="">
</body>

</html>